Occupants of dwellings and commercial structures have long benefited from the inclusion of a heating, ventilating, and air conditioning (HVAC) system that regulates the temperature and humidity within the dwelling or structure. Traditionally, the thermostat that controlled this temperature regulating equipment was a fairly simple electromechanical device that was simply wired to a heating device and/or to a cooling device. Once installed, the user need only move a selector switch between heating and cooling to designate which equipment was desired to be operated, move a selector switch between run and auto for a fan control, and rotate a dial to a desired set point temperature. No other user interface to the thermostat was needed or available, and no indication of system operation was provided.
Advances in control electronics have allowed the development of new, digital thermostats that may be programmed by a user to control the heating and cooling equipment in a much more energy efficient manner than the older electromechanical devices. These modern digital thermostats allow programming that can automatically set back the heat, for example, during periods when the dwelling or structure is not occupied, and can turn up the heat just prior to and during periods of occupation of the dwelling or structure. Indeed, many such digital thermostats allow for different programming options during different days of the week. For example, such a digital thermostat may provide for one programmed operation during the week and a different programmed operation on the weekend, to accommodate the different usage patterns of the occupants of that particular dwelling or structure.
While the advances that are being included in modern digital thermostats greatly enhance the users' comfort level and minimize the energy usage, the overall user experience interfacing with such a digital thermostat has not kept pace. Specifically, while such digital thermostats typically provide some form of user interface screen from which information is conveyed to the consumer, and from which the consumer may program the operation of the thermostat, such displays do not provide any indication that the heating or cooling equipment in the home is active.
To provide such indication of the operational status of the heating and/or cooling equipment, such digital thermostats now often include light emitting diode (LED) type indicators that illuminate when the heating and/or cooling equipment in the home is active. This provides an immediate visual indication of the operational status of the heating and/or cooling equipment. However, such LED indicators have led to several consumer complaints, and in some cases, reduction in performance of the thermostat itself.
Because an LED indicator needs to be bright enough to be visible during the daylight hours or within a lighted room to be effective, the amount of light output can be quite high. Unfortunately, many consumers have complained that such an LED indication is annoying, distracting, and unwanted in several situations. One such situation is when the thermostat is installed in, for example, a home theater where such a bright LED indicator detracts from the home theater experience. Another is when the thermostat is installed in a bedroom or other area where such a bright LED indicator would prove to be annoying.
In each of these types of situations, it has been known that consumers have used black electrical tape or other opaque tape to cover the LED indicators. While this solution removes the annoyance and distraction caused by the LED indicators, the consumer is left with no indication of the operational status of the heating and/or cooling equipment. The user is then forced to repeatedly remove the tape to determine the operational status, and replacing the tape when such LED indication would prove annoying or distracting. It has also been known for users to modify the internal electronics of the thermostat to disable the indicators altogether. However, such modification of the electronics may lead to spurious operation of the thermostat, damage to the thermostat, risk to the consumer, etc.
Another source of annoyance is from the intensity of the illumination of the backlit user display. Since many digital thermostats include a user display screen, e.g. a liquid crystal display (LCD), backlight illumination needs to be provided so that the information on the screen can be read in low light situations. To ensure that the information can be read clearly in different lighting conditions, the intensity of the backlight illumination is typically quite high. However, when the thermostat is accessed during the night or when it is quite dark in the room in which the thermostat is installed, the intensity of the backlight illumination is overwhelming, particularly to consumers whose eyes have adjusted to the dark.
There exists, therefore, a need in the art for a user adjustable display system for a digital thermostat that allows a user to adjust and/or disable the visual indication of the operational status of the heating and/or cooling equipment and the backlight illumination intensity of the user display.
The invention provides such a digital thermostat display system. These and other advantages of the invention, as well as additional inventive features, will be apparent from the description of the invention provided herein.